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Project Report Beneficiary No.17 ICPF Reporting period: Months 13 to 24 (01 June 2010 to 31 May 2011)
Křišťál, Jiří; Stavárek, Petr; Jiřičný, Vladimír
2011 - English
To assess the commercially available SO2 oxidation catalyst and select several for further testing we performed the extensive literature review. Based on that, we tested the selected catalysts for SO2 oxidation in experiments with the KIT lab microreactor, and started the detailed catalyst comparison based on the evaluation of the pre-exponential factor (A0) and activation energy (EA) calculated from the kinetic model by fitting the experimental data. To verify the possible design of a new sulph(on)ation reactor we performed the initial hydrodynamic experiments with gas-liquid two-phase flow in small channels.
Keywords:
microreactor; SO2 oxidation; process intesification
Available at various institutes of the ASCR
Project Report Beneficiary No.17 ICPF Reporting period: Months 13 to 24 (01 June 2010 to 31 May 2011)
To assess the commercially available SO2 oxidation catalyst and select several for further testing we performed the extensive literature review. Based on that, we tested the selected catalysts for SO2 ...
SOP - FMU LabVision Auto Export
Křišťál, Jiří
2011 - English
FMU LabVision Auto Export is an extension of FMU control system providing the means for the automated export of process data and calculation of its mean and standard deviation values.
Keywords:
FMU control system; export of process data; calculation
Available at various institutes of the ASCR
SOP - FMU LabVision Auto Export
FMU LabVision Auto Export is an extension of FMU control system providing the means for the automated export of process data and calculation of its mean and standard deviation values.
Voltage-step Transient in Redox Systems II. 1D Approximation (revisited)
Wein, Ondřej
2010 - English
Using the well-known Cottrell asymptote, voltage-step transient experiment could provide data on bulk concentration and diffusion coefficient of working depolarizer, essential in the liming-current techniques. However, the Cottrell asymptote is not directly applicable in an early stage of the voltage-step transient process,. There are three additional transport resistances that cannot be neglected at extremely high initial currents: Faradaic resistance at surface of working electrode, Ohmic losses in its intimate neighborhood, and the galvanometric constraint in the outer circuit (galvanometer, current follower, potentiostat). Non-linear effect of these additional transport resistances on the transient current is calculated in a 1D approximation, i.e. assuming uniform accessibility of the working electrode, for finite voltage steps.
Keywords:
voltage-step transient; cottrell asymptote; ohmic loss
Available at various institutes of the ASCR
Voltage-step Transient in Redox Systems II. 1D Approximation (revisited)
Using the well-known Cottrell asymptote, voltage-step transient experiment could provide data on bulk concentration and diffusion coefficient of working depolarizer, essential in the liming-current ...
The Next Flexible microPROCESSING Unit (FMU2) is Getting a Face
Maes, P.; Křišťál, Jiří
2010 - English
The report states the current status of the upgrade of the flexible microprocessing unit.
Keywords:
microreactors; process intesification; SO2 oxidation
Available at various institutes of the ASCR
The Next Flexible microPROCESSING Unit (FMU2) is Getting a Face
The report states the current status of the upgrade of the flexible microprocessing unit.
Design of Connectors for the High-Pressure Micromixers Testing at Pilot Plant Scale
Křišťál, Jiří; Pellens, L.
2010 - English
The report describes the desing of standardized connectors for the connection of various micromixers to the high-pressure rig in order to carry out the experiments at the pilot plant flow rates.
Keywords:
high-pressure connectors; micromixers; experiments
Available at various institutes of the ASCR
Design of Connectors for the High-Pressure Micromixers Testing at Pilot Plant Scale
The report describes the desing of standardized connectors for the connection of various micromixers to the high-pressure rig in order to carry out the experiments at the pilot plant flow rates.
Edge Effects in Voltage-step Transient I. Ohmic Losses in 1D Approximation (revisited)
Wein, Ondřej
2010 - English
Ohmic potential drop between the working and reference electrodes plays an important role in the early stage of the voltage-step transient process. Non-linear effect of the ohmic drop on the transient currents has been calculated for large voltage steps, assuming reversible behavior (negligible surface overpotential) of a redox couple O + ne = R. This report extends an older study by Wein (1991). In particular, it adds a series of analytic approximations and gives more accurate numerical solving.
Keywords:
voltage-step transient; ohmic loss; cottrell asymptote
Available at various institutes of the ASCR
Edge Effects in Voltage-step Transient I. Ohmic Losses in 1D Approximation (revisited)
Ohmic potential drop between the working and reference electrodes plays an important role in the early stage of the voltage-step transient process. Non-linear effect of the ohmic drop on the transient ...
Project Report Beneficiary No.17 ICPF Reporting Period: Month 01 to 12 (01 June 2009 to 31 May 2010)
Křišťál, Jiří; Stavárek, Petr; Jiřičný, Vladimír
2010 - English
To assess the current state of the art in sulphur dioxide oxidation an extensive literature review including scientific papers, patents and books was started. The literature review is focused on following topics: operation parameters, flow rate, concentration of substrates and impurities, kinetics, catalyst characterization, reaction mechanism and apparatus. Extracted information were evaluated and organized in the form of a data matrix.
Keywords:
microreactor; SO2 oxidation; process intesification
Available at various institutes of the ASCR
Project Report Beneficiary No.17 ICPF Reporting Period: Month 01 to 12 (01 June 2009 to 31 May 2010)
To assess the current state of the art in sulphur dioxide oxidation an extensive literature review including scientific papers, patents and books was started. The literature review is focused on ...
Final Report on Microprocessing of Fluids 2009 – 2010
Křišťál, Jiří
2010 - English
The final report summarizes the work carried out with the research agreement no. 170306.
Keywords:
microprocessing; complex fluids; fundamental understanding
Available at various institutes of the ASCR
Final Report on Microprocessing of Fluids 2009 – 2010
The final report summarizes the work carried out with the research agreement no. 170306.
Voltage-step Transient in Redox Systems III. Effect of the Current Primary Distribution via Nernst Model
Wein, Ondřej
2010 - English
In addition to the common transient diffusion (Cottrell), there are further transport results that cannot be neglected: Faradic resistance at surface of the working electrode, and Ohmic resistance in the bulk of streaming electrolyte solution between the working and counter electrodes. These additional resistances are analyzed here for the voltage-step transient (VST) process using the Nernst model of a two-electrode cell (no reference electrode). The Faradic resistance is considered for a single redox couple O + ne- = R according to Butler-Volmer electrode kinetics. The effect of Ohmic and Faradic resistances in VST is accounted for using two models: the recently updated 1D approximation and a new model that accepts primary current distribution for a circular electrode. It is shown that the 1D approximation introduces unacceptable errors.
Keywords:
distributed nernst model; ohmic and faradic resistance; primary current distribution
Available at various institutes of the ASCR
Voltage-step Transient in Redox Systems III. Effect of the Current Primary Distribution via Nernst Model
In addition to the common transient diffusion (Cottrell), there are further transport results that cannot be neglected: Faradic resistance at surface of the working electrode, and Ohmic resistance in ...
Motion of a Spherical Bubble in Neighborhood of a Falling Sphere
Vejražka, Jiří
2009 - English
This report focuses on a motion of a small spherical bubble, which rises in a still liquid particle and encounters a falling spherical particle. We consider the case of very small bubbles and of relatively large particle (whose size is much bigger compared to the bubble). The report provides expressions for forces acting on the bubble and equations for the bubble motion. The motion equations form a system of ordinary differential equations, which should be solved numerically. The purpose of this study is to provide a mathematical model, which would describe experimental observations by Hubička et al. (2009). In these experiments, a decrease of collision efficiency of the flotation process is observed if the particle is moving, compared to the case of still particle. Práce se zaměřuje na pohyb malé kulové bubliny, která stoupá v nehybné kapalině a střetává se s padající kulovou částicí. Je uvažován případ malé bubbliny a mnohem větší částice (s průměrem výrazně větším, než je velikost bubliny). Zpráva udává výrazy pro úříslušné síly, které je třeba uvažovat v pohybové rovnici pro bublinu. Výsledkem je pohybová rovnice, kterou je možné řešit numericky. Cílem práce je poskytnout matematický model, který by popsal experimentální pozorování Hubičky a kol. (2009). V těchto experimentech, které sledují kolizní účinnost flotačního procesu, byl pozorován výrazný pokles účinnosti v případě, že se částice pohybovala, ve srovnání s nehybnou částicí.
Keywords:
bubble motion; spherical particle; force model
Available at various institutes of the ASCR
Motion of a Spherical Bubble in Neighborhood of a Falling Sphere
This report focuses on a motion of a small spherical bubble, which rises in a still liquid particle and encounters a falling spherical particle. We consider the case of very small bubbles and of ...
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